What you say to someone who has just sneezed, to wish them good health. English borrowed the German word as it is, and in American English especially it sits beside bless you as a friendly automatic reply. You say it to the person who sneezed, not about yourself. It is informal, warm, and a little old-fashioned or playful in some mouths; younger speakers may only know bless you. Though actually, it is not a magic spell and not a medical comment — it is social glue, like holding a door. German speakers are saying ‘health’; English speakers are mostly performing the sneeze-ritual in a German costume.

（對剛打噴嚏的人說）祝你健康。英語更常說 bless you；台灣日常較少用這句德語，有時會開玩笑說「有人在想你」。